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Two finds .. comments please


Well-Known Member
Hi all,

I'm new to this forum - great place!
I've started shaving with straight razors recently. Since I'm a long-time addict on Japanese Knives I was pretty familiar with honing techniques and stones.
Last week I found tow stones in an old, small knife shop and I beleive them to be coticules. However, I would like to know more about them and maybe some of you guys can comment on them.
The pieces are of decent sizes: 200x50 for the bigger 0ne and 175x50 for the smaller one. The bigger one is quite inhomogenuos and has a reddish tint. The smaller one is more uniform greenish with small dark spots.
Interesting is the backing material that is different than the commonly seen blue BBB or slate. The color is brown and the material has relatively large pores. It almost reminds me of material with volcanic origin. I have tried the yesterday on a razor. However, since I'm not familiar with coticules yet and didn't take my time to really do it the right way as described here the results were only moderate.
Anyway, I hope some of you can add some information on thiese pieces. Here are the pictures.

Stone 1:

Stone 2:

Tnhanks in advance for your comments!
They indeed look like Coticules. I've never seen them with a backing like that. Perhaps some kind of coarse sharpening stone?
The one with pink hues looks like a Coticule n°18 form the Vault. The "grained" one definitely looks like the "La Grise" layer.
Did you get additional details from the seller, such as were he bought them, how long ago?

Kind regards,
welcome to,

Hi Bart,

not much more info from the seller except that he had them in a cardbox in his store for the last 8-10 years. It was quite a small shop and the guy did not make the impression as if he knew much about sharpening, let alone stones.
What actually puzzled me also is the brown backing. Never seen anythihing like it before. Well, my knowledge on coticules is limeted so that doesn't mean a lot but obviously it's something new for you too - interesting....
By the way, I gave them another try just before with your dilute method. Well, mediocre ... HHT with the red one is possible with some goodwill. No luck with the other stone yet, although I somehow really like that one. It has some "magic" aura that somehow seems to have a special attraction to me. Ok , now I'm getting esoteric ....

I just posted about a video about the "improved" Dilucot procedure in another thread. Maybe you watch that, to confirm the slurry behaves similarly, so we can be sure these are indeed Coticules.

If you can manage to pass a HHT, straight of a Coticule, you should be able to get an excellent shave, once that blade is properly stropped.
If the other one indeed is a "La Grise", which I think it is, it should be fairly easy-going. How much experience sharpening razors do you have? I don't mean any disrespect with that question. It took me several weeks of practice to get it right myself, and I had nearly 20 years of experience sharpening woodworking tools and shaving arm hair to check if I did well. But getting a comfortable edge on a straight razor turned out to be an entirely new challenge for me. I have to add that information about proper use of Coticule was rather limited at the time. Just to say, that it may take some time before you unleash the full potential of these hones.

You were talking about a cardboard box. Did it have any printing on the out- or inside?

In any case, I would try to use the backside (NOT on a razor) to find out if it has any significant abrasive properties on tool steel. I wouldn't be surprised it some kind of 300 grit synthetic sharpening stone. I could ask Maurice of Ardennes Coticule about it. Unfortunately, he's working around the clock right now, to get the quarry operational again after wintertime. So I really can't bother him right now, but next time we meet (in May), I'll ask him about this.

Best regards,
BlueDun, How easy are they to lap (or produce slurry)?.. on each side.

Welcome to
Hey all,

regarding my sharpening capabilities ... well, I'm coming from the knife world. I started getting into Japanes Knives some three years ago. Meanwhile, I have some nice handmade kitchen knives and also some collectibles. With the knives came the stones. Right now I own some ordinary combos, some DMT's, a set of Naniwa Choseras (400,1000,3000,5000), a Naniwa Super 10'000, and two japanese naturals, one Aoto and one Awaseto. Plus a bunch of strops (hanging, backed) partially pasted (CrOx). While I'm still far away from any japanese sharpening professional I manage to get a consistently sharp edge on any of my knives, regardless of the steel type, far beyound anything you can buy in shops. Of course this puts me nowhere close to be able to sharpen a razor on my first attempt. Yet, I think that this gave me some experienece how steel behaves, how to "listen" to stones, how to feel the drag, ... ya know what I mean.
So, recently I got into straight razors after reading about them on the net every once in a while. I have to adimit that I was addicted right away (I guess I'm telling no news here ...:rolleyes: ). I got my frist razor three months ago (a nice Revisor) and today there are already 8 pieces in my bathroom shelf. Some of them I got with the primary intention to use them as sharpening training objects. So by now I would say that I did about 25 complete sharpening sessions, experimenting with different stone combinations and improving my honing skills. I found that I get the best results with the Naniwa setup. First the Choseras 1000,3000,5000 (did I mention that I just LOVE these stones, but that's another story) then finishing off on the SS10'000, on to the paste strop and then the leather. With this I'm able to get a consistent HHT-3 after stropping and the shaving goes well (but I never had one from a "Master Sharpener" to compare). I also gave the Japanese naturals some tries but somehow did not find my way with them yet. And now come these two Cotis ....

So much seems clear: Judging by the slurry both are definitely Coticules. Booth of them raise a very nice and fine slurry that looks just the way it is shown in any videos/pictures I've seen so far.
Yesterday I gave both of them a try with a training knife which I dulled befor I started. I tried to stick (or at least lean to ) the updated diluticot method. As a general impression I can say that the grise seems to be a lot harder and has much less abrasive properties than the reddish one. I did 30 half strokes with milky slurry and some pressure with my index finger and the discoloration from shaved steel was just barely visible. The more I diluted the more I had the feeling of a almos glass-like surface. Under the microscope the edge looked quite nice and homogeneous but even after using a pasted strop and many strokes on leather I was not able to get a sucessfull HHT (althoug, after the first slurry session I could shave my arm hair). Since this was the second sharpening session I tried to use the knive to shave this morning anyway. I did some passess with the grain on my cheek and it shaved. It was far from great but it was not absolutely miserable either. Not so good that I would try to shave against the grain, though ... i don't know, but somehow this rock really semms to has some secrets to it.
The red stone was easyer to work with. After the first set of half strokes I had a clearly visible discoloration and could shave my arm hair. It seemed softer and gave me a bit more feedback in my hand. At the end, after stropping I managed to pop some hairs with a bit of goodwill. To bad I could not try that edge for a shave.
Regardless of these observations bear in mind that I am unexperienced with Cotis and therefore, the human factor may play a signifacant role here too.

About the backsides ... If you look what Murray Carter can do to a knive with a construction brick and a piece of cardboard, then question Is not really if an object can sharpen a knive but if it was INTENDED to do so. Regarding the brown backings I doubt that this is the case. The abrasive capabilities are mediocre at best and it will raise no significant slurry. I am also not sure if it is of synthetic origin. It looks so much different than any synthetics I have seen. It has pores of irregular size and the color is varying too. I would not bet anything on that but it really seems to be something like tuffstone.

I'm affraid that there is not more information from the shop where I got them. The storage box I pulled them from was nothing but exactly that, a plain old cardboard storage box with all sort of wheatstones in it (all but two completey unspectacular). The Cotis were not individually packaged. So no trace there ...

So it seems like a interesting puzzle to solve. Bart, if you find the time to ask back in Belgium that would be great! If you're interested I may even think about sending them out to you after getting some more tries on them myself. I will be gone on business trip for two weeks so I will not have the time to play with them until May. But of course I will continue to be in the Cafeteria and see if any more info pops up.

Have a good one all
Now it could well be a natural stone used as a backing, but so I am going out on a limb so here goes…

I suspect your Coticule is glued to a hard ceramic like a barber hone. Looking at the red side you can see little “voids” in the material typical of a vintage "Swaty type" barber hone (yes, some vintage barber hones do have voids just like that). It would be a simple matter to glue them together like gluing any other backing to a Coticule. That would explain why you get little or no slurry or cutting power from the red/brown side. Unlike a barber hone, that side may not have any abrasive particles because it’s the backing for the Coticule, instead of the commonly used slate or shist.

Again I could be wrong...
Do you think they are an older, coticule version of these?

The double side whetstone: Cotcarb
The cotcarb is, like the Coticule, a double side stone. It consists of a BBW top side and a Carburandum (synthetic stone) bottom side. The BBW has ca. 4000 grit and the Carburandum layer has 600 grit. The Carburandum side is used to do the hard work of preparing blunt knives, the BBW top layer will do the real sharpening.

Hmmm .. hard to tell.
I haven't seen one of these in reality. Do you have any close-up picture of the backside?
Or if you own one maybe you could have a look at my pictures where I have some close shots of the backside.

On the other hand .. as I found the backside not to be very efficient in removing metal I would not really want to use it to do any "hard work" on a knife.
A bit off topic but...
BlueDun said:
Since this was the second sharpening session I tried to use the knive to shave this morning anyway. I did some passess with the grain on my cheek and it shaved.
... do you shave with a knife? :blink:

Are you Crocodile Dundee kind of person?
:huh: :huh:

... not quite. Ok, ok, I admit that my terminolgy was maybe not 100% apptopriate. But hey, a razor is nothing but a special type of knife. Looking at it that way ... ;)

And really, you can shave with a regular knife too. Check youtube for Murray Carter and watch what he does. If I arrive at 20% of his sharpening skills one day I request to be called "Sir".

Hey Marek.
Not at all, don't worry :)
I'm not natively english either. Sorry if I made the impression to be upset.
Maybe I should have used more of these --> :w00t: :lol: B) :blush: :scared: :blink: :thumbup: :rolleyes: ;)

Don't complain Ralfy. You should be happy Polish is not lingua franca of the contemporary world. :lol:
I would be well stuffed then Maro, have you ever tried to find a good online Polish/English translator!! lol
I could imagine a fairly good Polish -> English translator.
Vice versa translation won't be that easy due to quite complex syntax of Polish. I've read a few instructions evidently translated that way. I was hardly able to get the point. :thumbdown:
But, as Matis said, we're ready to translate anything you wish. :rolleyes:


I asked Maurice about the weird backing of your Coticules. He instantly knew the answer. You're going to love this.:D

The backing of these hones is...

C O N C R E T E.

That's right. Concrete. The story is this: The company we now know as Ardennes Coticule used to call Burton, after Mr. Proper Burton, who founded it. When Mr. Burton retired, the company was taken over by Joseph Grogna (a geologist, still under the living and one of the most knowledgeable Coticule scientists ever). With labor cost rising rapidly, it was no longer economically feasible to glue to BBW, so Grogna started looking around for alternatives. He tried 2 different types of local slate, but since they're roofing types of slate, they split easily into rather thin sections, which makes them excellent natural roofing slate, but not very good for backing Coticules. Later on he started pouring a type of fine concrete with a brown pigment added. Maurice said it did a good job, although it absorbs water with great ease.
When Maurice took over the company from Grogna a few years later, he did not like the idea of gluing Coticules to man-made concrete. He found a Portuguese slate with the correct properties and didn't look back. When the supply of Portuguese slate dried out recently, they found a very similar Vietnam slate.

Kind regards,